Method and means of linking sausage

ABSTRACT

A machine for linking sausage has a pump, a stuffing tube, a casing on the stuffing tube, and a pair of linking chains downstream from the outlet end of the stuffing tube. A scale is located downstream of the discharge end of the stuffing tube and is operatively connected to the pump to increase or decrease the output speed of the pump as the weight of the encasing product decreases or increases, respectively from a predetermined target weight. The linking chains have spaced apart linking elements. A proximity sensor monitors the linking chains as they are rotating and senses variations in the distance between the linking elements as compared to a predetermined distance to determine stretching of the chains. A mass flow sensor is located on the machine adjacent the outlet of the pump to measure the mass of meat emulsion exiting the pump. The mass flow sensors operatively connected to the pump to increase or decrease the output of the pump as the mass thereof decreases or increases, respectively from a predetermined target mass. The method of linking sausage comprises the mass flow sensing of the output of the pump and the regulation of the pump speed thereby. The method further employs the use of a proximity sensor to monitor the linking chains to determine the stretching thereof. The method further includes the step of weighing the encased product and increasing or decreasing the output speed of the pump as the weight of the product decreases or increases, respectively with respect to a predetermined target weight.

This is a divisional application of Ser. No. 08/296,122, filed Aug. 25,1994.

BACKGROUND OF THE INVENTION

Sausage linkers such as that shown in U.S. Pat. No. 3,115,668 use metering gears to control meat emulsion flow. The gears cause detrimental smearing of the meat.

Prior art casing linkers often make it difficult for the operator to tie off the lead and tail end of the meat casing, which cause some wastage of meat.

Franks, sausages, hot dogs are most commonly stuffed into an "accordioned" closed end casing. The empty casing is set spinning about a "stuffing" tube. As the meat emulsion is pumped into the empty casing, the casing un-accordions and is pulled by gripping chains. The gripping chains have pinchers (butterflies) at predetermined distances. When a pincher squeezes the meat filled casing, the leading filled casing stops spinning, the trailing casing is still spinning about the stuffing tube. Henceforth a "twist" is incorporated into the strand of meat filled casing. Typically one and a half (1.5) full rotations is the optimum twist count.

Conveyors are most typically placed at the exit end of the sausage forming machine. The leading end of the meat filled casing (say two or three sausages) is hung over a hook. The same is true for the trailing end of the meat filled casing. As the leading and trailing ends hang freely they sometimes experience un-twisting between the formed sausages. The operator has to manually re-twist the two ends before "tying" off. This is slightly time consuming and/or annoying.

Further, existing linkers using linking chains cause the chains to stretch with use, and do not provide any accurate way of measuring this stretching so as to determine when the chain should be replaced.

Existing linking machines do not automatically weigh the product, and have no way to correct for weight variance.

Accordingly, features and objectives of the instant invention are as follows:

1. Mass Flow vs. Volumetric metering: By using a mass flow sensor to measure the flow of meat and thereby govern the meat pump the NL-14 has several advantages over a machine using metering gears. First, meat is less smeared using mass flow because it passes through a smooth stainless steel tube rather than a set of metering gears while being metered. This gives operators that ability to produce product with improved particle definition. Second, the mass flow meter is capable of measuring differences in meat density which can be analyzed by the PLC to provide important information about sudden difference in meat composition to the machine's operator.

2. Pressure Sensing: By controlling the flow of meat with an in line transducer (pressure sensor) rather than with metering gears the ability of the machine to produce large particle product is improved because the product is not smeared by metering gears. The transducer senses when meat is or is not required by sensing in line meat pressure and turns the meat pump on or off accordingly.

3. Twist Ramping: By adding additional twist to the lead and tail end of the casing the operator is given more time to tie off the casing before it is able to untwist. The additional twist is achieved by cycling the Twister through an RPM ramp in which the lead and tail end of the casting receive higher twist RPM then does the mid section.

4. Chain Stretch Test: By measuring the amount of stretch that has developed between butterflies on the linking chains the operator is able to gauge when the chains need to be replaced. The chain stretch is measured by comparing the known distance between a new set of chains of a given pitch with chains of the same pitch being tested. The distance between the butterflies is measured by a proximity sensor located near the chains as the chains rotate.

5. Auto weigh conveyor: By automatically measuring the weight of the product and automatically adjusting the machine to correct for any weight variance, the auto weigh feature enables the operator to test and adjust product weight without using a separate scale thereby saving time and increasing accuracy.

6. Follower Control: An ultra sound sensor mounted on the follower can automatically control various motors and clutches as it reaches different positions by traveling along with the follower rod.

SUMMARY OF THE INVENTION

A mass flow sensor is used to measure the flow of meat which thereupon controls the linker mechanism.

A pressure sensor is used to measure the flow of meat which thereupon controls the linker mechanism.

Means are provided to add an additional twist to the lead and tail end of the casing and the operator is given more time to tie off the casing before it is able to untwist.

A proximity sensor is located near the linking chains to measure the distance between linking butterflies to determine chain stretch.

A weighing device is provided to measure the weight of the product and automatically adjust the machine to correct for any weight variance.

A sonic follower control is provided to allow the follower to actuate various components of the machine.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front elevational view of the device of this invention;

FIG. 2 is a top plan view thereof;

FIG. 3 is an end elevational view as viewed from the right-hand end of FIG. 1;

FIG. 4 is a view of the device of FIG. 1 shown at a reduced scale with a conveyor attached to the outlet end thereof;

FIG. 5 is a top plan view of the device of FIG. 4;

FIG. 6 is a front elevational view similar to that of FIG. 1 but with the power train shown thereon;

FIG. 7 is top plan view similar to that of FIG. 1 but also showing the power train imposed thereon;

FIG. 8 is an end elevational view similar to that of FIG. 3 but shows the power train imposed thereon;

FIG. 9 is an enlarged scale end elevational view of the casing hopper;

FIG. 10 is a side elevational view of the device shown in FIG. 9 as viewed from the left hand side thereof;

FIG. 11 is a top plan view of the device shown in FIG. 9.;

FIG. 12 is a schematic view showing the gravimetric linking control (mass flow sensor);

FIG. 13 is a view similar to that of FIG. 4 with legends thereon showing the load cells associated with the conveyor;

FIG. 14 is a plan view of FIG. 13;

FIG. 15 is a schematic view of the pressure transducer linker control;

FIG. 16 is a perspective view of the pressure transducer linker control;

FIG. 17 is a perspective view of the ultra sonic follower sensor;

FIG. 18 is a view similar to that of FIG. 4 but shows the ultra sonic follower sensor; and

FIG. 19 is a plan view of FIG. 18.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The numeral 10 comprises a sausage linker machine having a frame 12 which is comprised from front 14, and 16 and 18, and top 20.

A conventional emulsion pump 22 is mounted on frame 12 and is in communication with a conventional hollow elongated stuffing tube 26 through which the meat emulsion is moved by pump 22. An elongated follower arm 24 is mounted on the top of frame 12. A casing hopper 28 is mounted on the top of frame 12. A chuck 30 is mounted on towards the discharge end of stuffing tube 26. A conventional set of linking chains 32 is mounted on frame 12 immediately downstream from chuck 30. Linked sausages move conventionally from the linking chains 32 through discharge tube 34 onto a conveyor 38 having a load cell 40 (scale).

A conventional mass flow sensor 44 (FIG. 12) is in communication with the output side of pump 22 and is operatively connected to the power source for linker 32 to control the mass flow of meat emulsion.

A proximity sensor 46 (FIG. 5) is mounted adjacent linker chains 32 to measure the distance between the conventional butterflies on the linking chain. The chain stretch is measured by comparing the known distance between a new set of chains of a given pitch with chains of the same pitch being tested. The proximity sensor 46 functions as the chains are rotated.

By using the mass flow sensor 44 to measure the flow of meat and thereby govern the pump 22, the meat is less smeared because it passes through a smooth stainless steel tube 26 rather than a set of conventional metering gears. This gives the operators the ability to produce product with improved particle definition. Secondly, the mass flow meter is capable of measuring differences in meat density which can be analyzed by a PLC to provide important information about sudden difference in meat composition to the machine's operator.

By controlling the flow of meat with an in line transducer rather than with metering gears, the ability of the machine to produce large particle product is improved because the product is not smeared by metering gears. The transducer senses when meat is or is not required by sensing in line meat pressure and turns the meat pump on or off accordingly.

The proximity sensor 46 (FIG. 5) measures the amount of stretch that has developed between butterflies on the conventional linking chains. The operator is therefore able to gauge when the chains need to be replaced. The chain stretch is measured by comparing the known distance between a new set of chains of a given pitch with chains of the same pitch being tested. The distance between the butterflies is measured by the proximity center while the chains are rotated, as described above.

A pressure transducer 48 (FIG. 15) is associated with the stuffing tube and is operatively connected to the linker so that under conditions of reduced pressure or increased pressure, the speed of the linker can be increased or decreased to accommodate for the changes in pressure of the meat supply.

FIGS. 17, 18 and 19 show the ultra sonic follower 50 on follower 24. The purpose of the ultra sonic follower 50 is that as the follower 24 moves longitudinally to move the casing on the stuffing tube 26, the element 50 can function to actuate various motors, clutches, etc. in the machine which need to become operative or inoperative at various stages of the longitudinal travel of the follower rod 24.

By automatically measuring the weight of the encased product and automatically adjusting the machine to correct for any weight variance through the PLC, the automatic weighing feature enables the operator to test and adjust product weight without using as separate scale thereby saving time and increasing accuracy. The scale 38 is operatively connected to the pump 22 so that increases or decreases in weight as sensed by the scale will cause decreases or increases, respectively, in the output of the pump.

The operator can add an additional twist to the lead and tail end of the casing and this is to provide more time for the operator to tie off the casing before it is able to untwist. The additional twist is achieved by cycling the twister through an RPM ramp in which the lead and tail end of the casing receive higher twist RPM's than does the mid section of the casing. The extra twist feature of this invention simply adds some percentage above the normal/typical one and a half twists to both the leading and trailing ends of the meat filled casing. For example: this extra twist could be from 2-4 complete twists between each sausage, then revert back to the normal/typical one and a half twists through out the middle 90% of the meat filled casing. This helps to eliminate the un-twisting experienced at the conveyor, while optimizing casing costs through 90% of the strand.

It is therefore seen that this invention will achieve all of its stated objectives. 

What is claimed is:
 1. The method of encasing sausages comprising, introducing a quantity of plastic meat emulsion into an elongated casing having opposite ends, twisting said casing at predetermined lengths to create a plurality of linked sections, twisting the lead and tail ends of said casing a plurality of additional times to retain the meat emulsion in said casing, and then tying off opposite ends of said casing before the plurality of twists are released. 